If the snake handling churches were consistent, they would also follow the second part of Mark 16:18 , “…and when they drink deadly poison, it will not hurt them at all.” Scripture is consistent that God can and will protect us, according to His will, as we are serving Him. Scripture is also consistent that we are not to put the Lord to the test ( Exodus 17:2 ; Matthew 4:7 ). Just as Jesus refused to jump off the pinnacle of the temple, even though God would send angels to protect Jesus, so are we to not intentionally put ourselves in situations that require God’s miraculous intervention. First Corinthians 10:9 , while not speaking directly of snake handling in churches, says it best, “We should not test the Lord, as some of them did — and were killed by snakes.”
Which of course leaves us with the question of why this snake-handling and poison-drinking was mentioned in the NWT in the first place.